title: Systemic review and meta-analysis of randomized clinical trials comparing primary vs delayed primary skin closure in contaminated and dirty abdominal incisions.
abstract: OBJECTIVE
  Surgical site infection remains a major challenge in surgery. Delayed primary closure of dirty wounds is widely practiced in war surgery; we present a meta-analysis of evidence to help guide application of the technique in wider context.
  
  
  OBJECTIVE
  To determine using meta-analysis whether delayed primary skin closure (DPC) of contaminated and dirty abdominal incisions reduces the rate of surgical site infection (SSI) compared with primary skin closure (PC).
  
  
  METHODS
  A systematic review of the literature published after 1990 was conducted of the Medline, PubMed, Current Controlled Trials, and Cochrane databases. The last search was performed on October 6, 2012. No language restrictions were applied.
  
  
  METHODS
  Randomized clinical trials comparing PC vs DPC were included.
  
  
  METHODS
  Two of us independently selected studies based on quality assessment using the Cochrane Collaboration tool for assessing risk of bias in randomized trials. Data were pooled using fixed- and random-effects models.
  
  
  METHODS
  Rate of SSI, as defined by the individual study.
  
  
  RESULTS
  The final analysis included 8 studies randomizing 623 patients with contaminated or dirty abdominal wounds to either DPC or PC. The most common diagnosis was appendicitis (77.4%), followed by perforated abdominal viscus (11.5%), ileostomy closure (6.5%), trauma (2.7%), and intra-abdominal abscess/other peritonitis (1.9%). The time to first review for DPC was provided at between 2 and 5 days postoperatively. All studies were found to be at high risk of bias, with marked deficiencies in study design and outcome assessment. When SSI was assessed across all studies using a fixed-effect model, DPC significantly reduced the chance of SSI (odds ratio, 0.65; 95% CI, 0.40-0.93; P = .02). However, heterogeneity was high (72%), and using a random-effects model, the effect was no longer significant (odds ratio, 0.65; 95% CI, 0.25-1.64; P = .36).
  
  
  CONCLUSIONS
  Delayed primary skin closure may reduce the rate of SSI, but current trials fail to provide definitive evidence because of poor design. Well-designed, large-numbered randomized clinical trials are warranted.
authors.affiliation: Royal Centre for Defence Medicine, Birmingham, England.
authors.forename: Aneel
authors.initials: A
authors.lastname: Bhangu
authors.forename: Prashant
authors.initials: P
authors.lastname: Singh
authors.forename: Jonathan
authors.initials: J
authors.lastname: Lundy
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Bowley
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D013530:Surgical Wound Infection / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D013536:Suture Techniques; D007507:Therapeutic Irrigation; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents